This section provides background information related to the present disclosure which is not necessarily prior art.
Vehicles powered by internal combustion engines have a fuel delivery system that stores and delivers fuels to the internal combustion engines. In general, the fuel system includes units that include a fuel tank, a fuel pump, a fuel filter, a sending unit, a fuel rail, fuel injectors, and a series of conduits that transports fuel between the units. Because various units of the fuel system contact fuel, some at elevated temperatures, the units desirably withstand thermal-induced and/or fuel-induced corrosion.
Spark Ignited Direct Injection (SIDI) is a variant of fuel injection employed in some non-diesel two and four stroke internal combustion engines. The fuel is highly pressurized, and injected via a common rail fuel line directly into the combustion chamber of each cylinder. Some engines may have multi-point fuel injection that injects fuel into an intake tract, or cylinder port. Directly injecting fuel into a combustion chamber requires high pressure injection; low pressure can be used to inject fuel into an intake tract or cylinder port. Some advantages of SIDI engines are increased fuel efficiency and high power output. Some SIDI engines may have reduced emissions levels. Such advantages are achieved, in part, by precise control over the amount and timing of fuel injected into the combustion chamber.
Moreover, many vehicles have internal combustion engines that are powered at least partially, if not completely, by alternative fuels, which help reduce petroleum use and greenhouse gas emissions. Some vehicles, i.e., flexible-fuel vehicles or dual-fuel vehicles (also known as “flex-fuel vehicles”) have internal combustion engines that are designed to run on more than one fuel, such as a blend of gasoline and an alternative fuel.
One such alternative fuel is ethanol, which may be generated from corn, grain, or other biomass sources. Whereas some vehicles have internal combustion engines that run on pure 100% ethanol, i.e., E100 fuels, other vehicles have internal combustion engines that run on ethanol blended fuels, such as E5 (5% ethanol), E7 (7% ethanol), E10 (10% ethanol), E20 (20% ethanol), E22 (22% ethanol), E25 (25% ethanol), E70 (70% ethanol), E75 (75% ethanol), E85 (85% ethanol), or E95 (95% ethanol) fuels. Because ethanol causes corrosion on various materials, vehicle components, such as units of fuel delivery systems, that contact fuels containing ethanol benefit from coatings that resist corrosion. With the increasing use of fuels containing ethanol throughout the world, there is a need for new coatings that withstand corrosion caused by ethanol or a combination of ethanol and heat.